Researchers add the tannin slurry drop by drop onto a rotating wheel.

Researchers add the tannin slurry drop by drop onto a rotating wheel.


John Lombardi, president of Ventana Research Corp., Tucson, combined phytochemicals from green-tea extract, synthetic proteins, and an abrasive to produce a slurry said to be three to four times faster at polishing magnetorestrictive heads than the material currently used. Also, the slurry is environmentally friendly to boot, unlike many of the solvent-based slurries used today.

The ceramic debris particles scrubbed away during hard-drive head polishing are submicron-sized and cling to the surface, making them difficult to remove. Tannin phytochemicals have a strong attraction to these particles and tightly bind to them. The phytochemicals give the particles an electrostatic charge, causing them to be repelled from other particles and the head surface. This makes them float so they can easily wash away with water.

Because of their attraction to metals and ceramics, tannin phytochemicals may be used in mining, cancer treatment, high-performance adhesives, specialty coatings, removal of metal contaminants from water, and wastewater treatment.